Prognostic Value of Coronary CTA in Stable Chest Pain: CAD-RADS, Coronary Artery Calcium, and Cardiovascular Events in the PROMISE Trial

Background and Objective: To compare the 2016 Coronary Artery Disease Reporting and Data System (CAD-RADS) for coronary CT angiography (CTA) to traditional stenosis categories and the coronary artery calcium score (CACS) for predicting cardiovascular events in patients with stable chest pain and suspected CAD. Methods: PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial participants’ CTAs were assessed by a central CT core lab for CACS, traditional stenosis-based categories, and modified CAD-RADS grade including high-risk coronary plaque features (HRP). Traditional stenosis categories and CAD-RADS grade were compared for the prediction of the composite endpoint of death, myocardial infarction, or hospitalization for unstable angina over a median follow-up of 25 months. Incremental prognostic value over traditional risk factors and CACS was assessed. Results: In 3,840 eligible patients (mean age: 60.4±8.2 years; 49% men), 3.0% (115) experienced an event. CAD-RADS (c-statistic 0.747) had significantly higher discriminatory value than traditional stenosis-based asessments (c-statistic 0.698-0.717; all p for comparison ≤0.001). With no plaque (CAD-RADS 0) as the baseline, the hazard ratio for an event increased from HR 2.43 [95% CI: (1.16-5.08)] for CAD-RADS 1 to 21.84 [95% CI: (8.63-55.26)] for CAD-RADS 4b +5. In stepwise nested models, CAD-RADS added incremental prognostic value beyond ASCVD risk score and CACS (c-statistic 0.776 vs. 0.682, p<0.001), and added incremental value persisted in all CACS strata. Conclusion: These data from a large representative contemporary cohort of patients undergoing coronary CTA for stable chest pain support the prognostic value of CAD-RADS as a standard reporting system for coronary CTA.